A European probe bearing down on the planet Venus is set for a Tuesday arrival to take a close look at the world’s soupy atmosphere. After five months of spaceflight, the European Space Agency’s (ESA) Venus Express orbiter is expected to fire its main engine in a nearly hour-long maneuver to begin its planet-watching duties.

“I don’t dare get too excited because we have to be calm if there are any problems,” Venus Express project manager Don McCoy told SPACE.com. “It will feel good once we know we’re in orbit around the planet.”

I’m assuming that they won’t have any measurement errors in their orbital program.

Venus Express carries seven primary instruments, many of which were spares left over from previous ESA missions such as the agency’s Mars Express and comet-bound Rosetta programs, to peel back the layers of the Venusian atmosphere. Researchers hope the spacecraft will unveil the source of Venus’ dense, turbulent and toxic atmosphere.

“We think that volcanism is the mechanism that would produce that atmosphere,” Svedhem said. “And if we find that this is the case, well that I think would be very exciting.”

Then again, maybe we’ll find out that under-regulated Venusian industry was behind the planet’s runaway greenhouse effect.